| 摘要 |
<p>Appts. for detecting the surface of a molten metal bath to ensure a pre-determined depth of immersion of the measuring head of test probe, in which a tubular tip of combustible material e.g. cardboard, is fitted on a hollow tube fixed to the probe-carrier, the pneumatic signal produced by the pressure of the combustion gases being used to arrest the immersion motion of the probe, is improved by placing a device in the tubular cardboard tip which has an elongated form with one part of its external weld profiled in such a way that only a very small clearance is left between it and the internal wall of the tip and virtually all movement is prevented, whilst the other part of the external wall is recessed or cut away so as to permit the passage between it and the inner wall of the cardboard tip of the gas produced by combustion of the end of the tip, the cutting away being such that the trajectory imposed on this gas involves several changes of direction and successive points of flow reversal and terminates in a longitudinal part inserted in the central part of the device.</p> |
